As far as being a writer goes, there are numberless beginnings and there is only one. Any person who earns a living by making words follow each other in more or less sensible ways will find it perfectly possible to invent all kinds of influences and impetuses for public consumption: the good English teacher, the bad English teacher, the First Great Book they read, the First Awful Book they read, the reading parents, the non-reading parents, the need of books, the presence of books, a disabling accident in childhood, a robust childhood, a tendency to dream, a tendency to flee dreams, the touch of a certain sunset over a certain view and the sound of geese going somewhere the author realises he or she will never be. Equally, if that same author reaches any kind of general publication, horribly quickly there will come journalists and academics and critics and friends and acquaintances and strangers and readers and relatives who will eagerly provide almost endless reasons for the writer and the writing. Many of these observers will be completely, even professionally, sure that they've hit on the heart of the matter, the truth.

But the truth is that you are a writer, because you are made that way. Which has been said before, I know - but what does it mean?

For example, you are not quite made a writer in the way that you are made blue-eyed, or diabetic. Writing is more of an inbuilt disposition - some children, suitably triggered, will grow up to perpetrate random murders: others, suitably triggered, will become heroin addicts, or clerics: still others will write. The trigger for writing appears to be very finely tuned - it may be sprung by chance qualities of light, coincidences, or any of the unpredictable odds and ends mixed up in the simple presence of everyday life. And, going back to those clerics, we might also describe the predisposition to write as a vocation, because it seems to be a need that comes from without as well as within. It is ours, but it plays upon us, has an independent existence which sometimes argues with our own. This calling, like any other, can be resisted, abused, disappointed, or simply drummed into silence by external forces.

And, even taking the disposition into account, being "born a writer" does not imply that the budding typist won't have to work at it just as hard as they might if they'd been born a policeman, or a fishmonger, or nothing identifiable at all. I might also point out that being born a writer can often feel paralysingly similar to being nothing identifiable at all, given that writing is an unlikely and ephemeral occupation, rarely respected until it has produced considerable fruit. It is almost always inexplicable to others until you have published at least a few books, and even then it can still be tricky. And whatever work it moves you to will not look like work, because the hours you devote to your writerly calling may seem perilously close to sitting down and staring a lot and will produce unmistakable (if occasionally angst-ridden) signs of satisfaction. Your progress will be irregular, baffling to quantify. It will also be deeply personal and, because of this, the idea that anyone can teach you how to become a writer, or how to write, is a myth.

Still, it may be that other writers - inside and outside all manner of institutions - may help you to find out who you are and how you think and how you write. Although, being a writer (and therefore prone to self-obsession) you probably won't thank them for it and, in any case, you will be doing that yourself, simply because part of writing is learning how - for ever and ever, writing is learning how. There are no short cuts. The art is in hunting out all of yourself, in putting your totality to work.

This may seem rather gruelling, if not frustrating, but it is also wonderful and, rather handily, exactly what the reader needs. One of the things we look for when we read is just that level of commitment, that totality. We seek out the full realisation of a unique presence, a voice other than our own; the viewpoints of human beings beyond ourselves; the precision of experiences we cannot have, described by somebody we cannot be. When we read we can go where the geese are, because someone took pains to go there before us and write the way. The writer gives us two miracles, a world other than that which we inhabit and the ghost of their company, their voice.

· This is an extract from a piece which appeared in the US as part of the Contemporary Authors Autobiography series, and was read at the Edinburgh Books Festival.